Both Gram-positive and Gram-negative bacteria can release nano-sized lipid bilayered structures, known as membrane vesicles (MVs). These MVs play an important role in bacterial survival by orchestrating interactions between bacteria and between bacteria and host. The major constituents of MVs are proteins, lipids and nucleic acids. Due to the immunogenicity of the membrane lipids and/or proteins of the MVs, in combination with adjuvant danger signals and the repeating patterns on the nanosized surface, MVs can effectively stimulate the innate and adaptive immune system. Since they are non-replicating, they are safer than attenuated vaccines. In addition, by genetic engineering of the donor cells, further improvements to their safety profile, immunogenicity and yield can be achieved. To date, one MV-based vaccine against Neisseria meningitidis (N. meningitidis) serogroup B was approved. Other (engineered) MVs in the pipeline study are mostly in the preclinical phase.

革兰氏阳性细菌和革兰氏阴性细菌均可释放纳米级脂质双层结构，称为膜囊泡（MVs）。这些MV通过协调细菌之间以及细菌与宿主之间的相互作用，在细菌存活中发挥重要作用。MV的主要成分是蛋白质，脂质和核酸。由于MV的膜脂和/或蛋白质的免疫原性，结合佐剂危险信号和纳米表面上的重复模式，MV可以有效刺激先天性和适应性免疫系统。由于它们是非复制型，因此比减毒疫苗更安全。另外，通过供体细胞的基因工程，可以实现对其安全性，免疫原性和产量的进一步改善。迄今为止，一种基于MV的疫苗批准了脑膜炎奈瑟氏球菌（N. meningitidis）血清群B。管线研究中的其他（工程）MV大多处于临床前阶段。